V-type torsion bar tillage tines

ABSTRACT

The invention provides a spring assembly and an energy absorbing linkage wherein end constraints on an elongated resilient member are effective to place the elongated member in torsion, such torsion permitting large deflections of the spring or linkage while maintaining a relatively low stress level in the resilient member. The spring assembly can be conveniently made in the form of an energy linkage unit, such a unit being suitable for building planar or lattice spring structure, or for use in an installation as a means of alternatively storing and releasing energy.

United States Patent 1 Ward [ 1 June 5, 1973 [54] V-TYPE TORSION BARTILLAGE TINES [75] Inventor: Walter H. Ward, Vereenigning, Transvaal,Republic of South Africa [73] Assignee: South African Farm ImplementManufacturers Limited, Vereeniging, Transvaal, Republic of South Africa[22] Filed: Oct. 8, 1971 [21] App]. No.: 187,664

[52] US. Cl ..267/l54, 267/57 [51] Int. Cl. ..Fl6l' 1/16 {58] Field ofSearch ...267/l54, 57

[56] References Cited UNITED STATES PATENTS 3,337,236 Peterson ..267/572,797,434 7/1957 Vigmostad ..267/l54 2,591,281 4/l952 Musschoot.........267/l54 3,276,762 10/1966 Thomas ..267/l54 Primary Examiner.lames B.Marbert Attorney-RobertL. Farris [57] ABSTRACT The invention provides aspring assembly and an energy absorbing linkage wherein end constraintson an elongated resilient member are effective to place the elongatedmember in torsion, such torsion permitting large deflections of thespring or linkage while maintaining a relatively low stress level in theresilient member. The spring assembly can be conveniently made in theform of an energy linkage unit, such a unit being suitable for buildingplanar or lattice spring structure, or for use in an installation as ameans of alternatively storing and releasing energy.

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sum 090F10 lnvenlor WALTER H. WARD M WM A ltorneys V-TYPE TORSION BARTILLAGE TINES The present invention relates to energy storing linkagesand especially to spring assemblies therefor.

According to the present invention a spring assembly consists of anelongated resilient member, first and second load attachments positionedon the member at spaced locations, the line extending between themdefining a longitudinal axis, said first load attachment being adaptedto apply torque to said resilient member, said second load attachmentcomprising first, second and third journal elements wherein said firstjournal element and said second journal element are connected by primarypivot means for pivotal movement relative to each other about a primaryaxis, and the second journal element and third journal element areconnected by secondary pivot means for pivotal movement relative to eachother about a secondary axis, said third journal element being fixed toor integral with said resilient member.

Preferably the primary pivot axis is inclined to said longitudinal axisand the secondary axis is arranged perpendicular to said primary axis.

According also to the present invention an energy absorbing linkage unitcomprises two spring assemblies as defined above wherein the first loadattachment is common to both resilient members and transmitsequilibrating torque from one resilient member to the other and whereinsaid first journal element is common to both assemblies.

According also to the present invention an energy absorbing linkagecomprises a plurality of energy absorbing units connected together.

Further the invention includes an installation incorporating a linkageunit as referred to wherein angular displacement of the spring through90 causes an energy input and a further deflection through 90 causes arelease of energy. Alternatively the resilient member is pretwisted onassembly so that the first 180 of deflection causes an energy input anda further deflection through 180 causes a release of energy.

The embodiments of the invention will now be described with reference tothe accompanying drawings of which:

FIG. 1 is a diagram of a representative spring assembly in accordancewith the invention;

FIG. 2 is a detail of a part of the spring assembly in FIG. 1;

FIG. 3 is a vector diagram of moments as applied to the embodiment inFIG. 1;

FIG. 4 illustrates a bending moment, torque and stress diagramrepresentative of FIG. 1;

FIG. 5 is a polar diagram representative of the function of theembodiment in FIG. 1;

FIG. 6 is a further embodiment of spring assembly according to thepresent invention;

FIG. 7 is a vector diagram of moments as applied to the embodiment inFIG. 6;

FIGS. 8 14 show various views of an agricultural chisel plow tineembodying the present invention;

FIGS. 15 and 16 show a side elevation and plan view of further chiselplow tine embodiments of the present invention;

FIGS. 17 to 27 illustrate various views of energy storing linkagesemployed in a variety of possible applications in accordance with thepresent invention;

FIG. 28 is a view of a spring assembly in which the spring rate can beadjusted in accordance with the present invention; and

FIGS. 29 to 31 are plan, side and end views of a representativeembodiment of a resilient linkage member in accordance with the presentinvention.

FIGS. 1 and 2 show the moments acting on the end of blade 10 at springattachment 12 which constitutes the second load attachment. The upwardor bending moment M is generated by the external forces E applied to thefar end of the blade 10 which constitutes the first load attachment. Forconvenience these are represented by equal and opposite loads. Themoment M and the reactive moments R and T are all represented as vectorsin the right hand or clockwise direction (which could becounterclockwise, of course, depending on direction of bending moment M)as shown in FIG 3. The clevis 14, which constitutes the second journalelement can be connected to the boss 16, which constitutes the thirdjournal element, by pivot pin 18 and is itself rotatable on a stub axle19 in a bore 20 in ajournal member 22, which constitutes the firstjournal element. The longitudinal axis of the resilient member isdesignated I... The axis of bore 20, being the primary axis, isdesignated P. The vertical axis corresponding to the primary axis, isdesignated S. The axis about which the bending moment M acts isdesignated N. The clevis 14 cannot generate any moment about axis Pbecause it is free to rotate on stub axle 19. It can only generate amoment R in the plane of the clevis a component of which will balance M,i.e. R cos 0 M where 6 is the angle between axes P and L. The othercomponent, R sin 0, is balanced by moment T which is supplied by atorque arising from twist of the blade. In FIG. 1 the first loadattachment 11 is represented by parallel bars 24 between which the blade10 can slide vertically and which react the torque T. The torquereaction point 26 on blade 10 lies between bars 24. Thus, the primepurpose of the first load attachment is to react the torque T. Byneglecting possible side effects from other forces T M tan 6, andwhatever the variation in the forces E, there will be a variation in Tgoverned largely by the above relationship.

The deflection of the whole spring assembly is found, at least to afirst approximation, by considering the twist in that portion of theblade 10 under torque i.e. between boss 16 and bars 24. The blade 10will have inherent characteristics of length, sectional dimension andelastic modulus of material and in general the twist is given by theequation:

Where 4) angle of twist T torque c torsional rigidity l= effectivelength of the blade In general 0 is a function of the shear modulus ofelasticity, the area of cross section and the moment of area inertia ofthe cross section. This and the length become an invariable factor for agiven blade 10. The angle of the blade 10 moves up is denoted t1: and ingeneral terms can be regarded as the angular deflection of the torquereaction point 26. The relationship between the angle 0, Q5 and \l; is:

= 1 cos U-lcos 9 for a single blade such as 10. being fixed for aparticular structure, cos 0 will be less than unity and the angulardeflection '11 will usually be somewhat larger than the blade twistangle 4). The deflection of the blade 10 in bending under moment M willbe easily calculated but if the blade has the proportions shown in FIG.1 it will be much smaller than the deflection due to twist- Referringnow to FIG. 4, this represents the bending moment and torsion diagramalong the length l of the blade 10 and are not to any particular scale.The bending moment M at the boss 16 generates the stress distributionshown on the right. It will be seen that the extreme fibers of the blade10 under bending are heavily stressed but that the imposition of atorsion does not add to this stress at all. Similarly, the centralregion is stressed by the torsion and the imposition of the bending doesnot contribute any large additional stresses in this region. Thus itaffords the possibility of being able to use some material of lower costthan spring steel.

The blades 10 can be designated to resist the bending loads which are tobe experienced and can then be converted into springs of suitablecharacteristics by selection of 0 (the angle of inclination) between theprimary axis P and the longitudinal axis L. When 0 0 there will be noreaction at all from the second attachment and when 0 90 there will beno torque applied to the blade and no corresponding torsionaldeflection.

The broader aspects of the invention as regards deflection and movementwill now be described with reference to FIG. 5. The spring may bemounted so that it can rotate in a vertical plane as seen in FIG. 1through one or more complete revolutions. The first load attachmentwould be such as to preserve its torque reaction properties throughoutthe movement which would be generally about axis N. For this purpose thebars 24 have been shown as parts of spaced circular rails in FIG. 1.Assume that the blade 10 is shown in its free state in FIG. 1 and thatmovement occurs in an upward and generally anti-clockwise direction fromthis position. Assume also that the angle t]; increases from zero duringthe movement. During the first 90 of movement the spring blade 10 willbe deflected and will be absorbing energy until 90 position is reached.Further movement from this point will reduce the deflectionprogressively and there will be an energy release until when ill 180 andthe spring will be back in its free state. During the third andfourthquadrants of movement there will occur an energy storage followed by anenergy release respectively.

FIG. 5 shows a polar diagram from which the geometry of the springdeflection in terms of the three angles can be studied. This diagram isbased on the formula previously given. The radial lines define angulardisplacement tli, the contours define the value of 6 (the angle betweenthe primary and longitudinal axes) and the angle of twist d) is given bya vertical scale alongside of the polar diagram. It has just beendescribed how energy input occurs in the first and third quadrants andenergy release occurs in the other two quadrants as the angle l1:increases. However at 90 or T.D.C. (top dead center) the spring goes oncenter with maximum energy locked in and this energy may be released byeither continuing the rotation or by reversing it. Reference is made tothe areas shaded at (b 5 to 10 and d) 25 to 30 for the 6 30 contour. Theenergy, which is proportional to these shaded areas put into the springfor 5 of deflection is much less nearer the T.D.C. position than earlierduring the total deflection. This means that the energy storage rate athigh deflection is lower than at lower deflection. In the pastconsiderable thought has been devoted to achieving effective springcharacteristics of this kind by the use of elaborate linkages. Therelease of energy is at an increasing rate as the blade approacheszero-torsional deflection.

It is possible to make a storage cycle extend over 180 by employingpretwist of the resilient blade 10. Such an arrangement is shown in FIG.6. The blade 10 is twisted and constrained at the first load attachmentby means of a block 25 but is permitted to move in an are between thebars 24 as before. Stops 28 are introduced to constrain the blade at thesecond load attachment end. With reference back to FIG. 5, assuming in aspring where 0 45 of pretwist, i.e. 45, has been introduced, then thescale of twist angles is changed from the range 45 to 0 to 45 to therange of 0 to 45 to and hence the zero for this scale is move to 0' atB.D.C. (bottom dead center). Consequently, the 180 angular from B.D.C.to T.D.C. will cause 90 of twist in one direction, i.e. acontinuousenergy input over two quadrants. Movement through the remaining twoquadrants (or reverse movement) will release the energy. The amount ofpretwist does not have to be as much as 45 degrees and in the case where\l/ 17 and 6 30 the base line from which to measure angle ill would bethe 150 330 radial line and the T.D.C. or maximum twist point wouldoccur after of angular deflection.

If a stop 28 is arranged, say 5 degrees after T.D.C. point, the spring,having passed over T.D.C., will not return and will stay against thestop thus constituting an over-center device.

FIG. 6 also shows an arrangement in which a spring assembly is providedwith a second load attachment having a provision for selectively varyingthe angle 0. The first journal element 22 is mounted on a rail 32 andcan be clamped in position by a screw 34. It will be seen that when theangle between N and P becomes zero the axis P is coincident with axis Nand when 0 becomes negative the blade 10 twists in the oppositedirection on receiving the same external loads. The corresponding vectordiagram when 0 becomes negative value is shown in FIG. 7.

Reverting to a 360 movement with two storage and two release cycles itshould be noted that one storage/- release cycle takes placeby torsionaldeflection of the blade 10 in one angular directioni.e. plus qb, andduring the other cycle in the other direction i.e. (1:. It is possibleto restrain the blade 10 against angular deflection only in one of thesedirections and to let it go free in the other.

In the foregoing description it has been assumed that one end of theassembly is fixed and the other parts of the spring assembly moverelative to it. Clearly the other end could be fixed if desired withoutaffecting the fundamental operation. I

If the characteristics of the blade and the choice of angle 6 is suchthat a large twist in the order of 90 occurs for a given load then thetotal bending characteristics will change because of progressive changein the bending section along the blade. Thus the total deflection mayhave a large proportion of it attributable to bending deflection. From astress point of view this is not desirable because the stresses becomeadditive but it may be acceptable in certain applications.

One of the difficulties of the spring assembly described in FIGS. 1 and6 is the nature of the first load attachment which has to provide atorque reaction irrespective of the angular deflections and theprovision of a static torque reaction member over a large arc is ofteninconvenient.

This difficulty is overcome by arranging the spring assemblies in pairsso that the torque from one spring equilibrates that from the other.This can be done in at least two ways exemplified in FIGS. 8 to 14 andFIGS. 15 and 16.

FIGS. 8 to show in side elevation, lower plan view and partial endelevation, a chisel plow tine assembly 40 mounted on a toolbar 41 whichcarries a movable bracket 42 clamped to it by a bridge piece 43 andbolts 44. A spring attachment assembly 45 is bolted to the underside ofthe bracket 42 by bolts 46. The support assembly 45 consists of two mainparts. These are shown, for the sake of clarity, separated from eachother in FIGS. 13 and 14 respectively and in assembled position in FIG.12. One part is constituted by a block 47 which has a central circularaperture 48. The bolts 46 pass partially through this aperture as seenin FIG. 11. Two keyways 49 and 50 are provided in the aperture 48 of theblock at diametrically opposed positions. A projecting boss 51 is boredto accept a long pin 52 shown in FIG. 9. The other part is a clevissupport 53 shown in FIG. 12 and has a cylindrical central portion 54having an annular groove 55 cut in its periphery. The central portion 54is adapted to fit snugly into the aperture 48 in block 47 and the bolts46, when inserted, partially pass through the groove 55 and hold thecentral portion 54 in position while enabling it to be rotated. Twobosses 56 each project at equal angles to the central portion and eachof these is bored to receive stub shafts 57 which each carry at theirouter ends a clevis 58. FIG. 12 is a plan view of the clevis supportassembly.

FIG. 14 shows a detail of one clevis 58 pinned to a blade adaptor plate59 with a pin 60 which is fast with the latter by having a bolt 61 passthrough both. The bolt 61 and a second bolt 62 also pass through the endof a spring blade 63 to hold the blade end fast with the plate 59.

Thus the construction is such that once the clevis support 53 is fixedin the block 47 by a key in an appropriate keyway 49 or 50, the clevises58 are permitted to rotate freely in the bosses 56 subject to theconstraints applied by the blade 63. The blade support plate 59 is alsopermitted to swivel freely on the pin 60 but is also subject to springforce constraint.

The spring blades 63 on each side side extend to the right, as seen inFIGS. 8 and 9, to form a mounting for the tine 70. A torsion lockoutyoke member 71 is applied at the end of the straight portions of theblades 63. This is a bracket having two slots 72 through which theblades 63 pass with small clearance.

The construction of chisel plow tine assembly described in FIGS. 8 to 14is designed to transmit certain loads to the frame by means of tool barmounting as sembly 40. These loads are all generated at the tine and ingeneral their resultant is in a rearward direction and displaced belowthe apex of the two blades which constitute a Vee. These originatingforces are carried into the structure and appear as a force and abending moment at the yoke 71. The force places both blades 63 in purtension and this is carried through the clevises 58 and the supportassembly 45 to the bracket 42 and tool bar 41. Negligible deflectionoccurs during the transmission of this force through the springassembly. The bending moment present at the apex is divided into equalparts and each passes along a blade 63 to a respective plate 59 as aconstant bending moment. This is applied to the respective clevis 58with the results described previously with reference to FIG. 1 exceptthat the torques carried by the two blades 63 are equal and opposite andare mutually equilibrated by the yoke 71.

FIGS. 15 and 16 show in side elevation and plan view a chisel plow tinemounted on a parallel arm linkage unit wherein the spring assemblies aremounted one above the other. The tine point is simply mounted on acurved bar 74 which is bolted to the foot of a standard 75. The standard75 is carried by two vertically spaced blade spring assembliesconstituted by two blades 76 and 77 pivoted on respective clevises 78and 79 themselves rotatable in clevis supports 80 and 81 which areintegral with or fixed to one of a pair of clamp brackets 83 and 84.Bolts 85 hold the clamp brackets on to a square toolbar 41. It will beseen that the clevises 78 and 79 are equally and oppositely orientatedon each side of a common vertical plane of the blades 76 and 77 andtransmit equal and opposite torques arising from vertical loads appliedto the standard 75. It should be recognized that horizontal forces andbending moments arising from ground contacts are likely to be taken astension and compression loads in the blades and only vertical shearforces causing bending moment at the front ends of the blades 76 and 77are likely to cause torsional deflection. With particular reference toFIG. 16 it will be seen that in the unloaded state the two clevises forma hinge axis about which the tine can pivot quite freely but as soon asit is loaded in bending and by draft loads it will tend to centralizepartially due to the uneven torsion reactions generated. It can bearranged that a tine of this kind be tuned to vibrate from side to sideto provide a soil shattering action if such is desired.

Turning now to arrangements involving multiples of paired springassemblies which can be conveniently termed spring units, FIGS. 17 and18 show a tine wherein several Vee springs 81, 82, 83 are nestedtogether and each Vee blade provides its own torque equilibration acrossthe apex of its Vee. The opposite front ends of the Vees are mounted inopposite members 84 which constitutes the first journal element referredto. The inner Vee blade 81 only is clamped between the locking plate 87,the others being free to accommodate differential movement withoutinhibiting the spring action.

FIGS. 19 and 20 show an arrangement employing several single but pairedblades 90, 91-91, etc. In this case each blade has its own individualpivot pin 9292 etc. which again constitutes the second journal element.The arrangement as a whole consists of similar upper and lowerassemblies 94 and 95 suitable for mounting a wheel 96 of a vehicle.

While the arrangements shown in FIGS. 17 to 20 show arrangements ofspring units in parallel, the following figures show various forms ofend connected spring units.

FIGS. 21 and 22 show in plan and side elevation respectively anequalizer bar wherein two units 101 and 102 are mounted on a singlesupport assembly 103 the latter constituting the first journal elementfor all four of the second journal members 104 and is itself journalledto rock in a pair of hangers 105. Loads would be applied or reacted atthe apices of the two units which are bolted together and be carriedthrough to the hangers 105.

FIGS. 23 and 24 show an arrangement of multiple spring units wherein oneend of each unit is suspended by a clevis 111 journalledin a commonfirst journal element 112 and the apices are pin connected together. Theunits, in groups of four are connected in a plane to make a large springcomplex capable of large deflec tions to the extent that the two loadpads 113 meet in the middle.

FIGS. 25 and 26 show an arrangement wherein both ends of the blades 121are mounted on clevises 122, 123 which are journalled in respectivefirst journal elements 124, 125 the multiplicity of springs defining acomplex similar to FIGS. 25 and 26. It should be noted in this casehowever that load is applied by arrows 126 as a linear force throughclevis 124 to the blade. This results in a moment at the other end whichgenerates torque at 124 in one direction. Similarly a torque arises fromthe reaction forces 127. It is arranged that the torques cause the sametwist in the blade i.e. one in one direction at one end and the other inthe other direction at the other end.

FIGS. 27 shows an arrangement wherein blade units having pin connectedapices are arranged symmetrically in a three dimensional lattice. Threedouble units would seem to be the minimum necessary to sustain a complexof this kind. More double springs would be incorporated with anorange-segment effect and would be limited at one level by the width ofthe spring units. Several levels, columns, and ranks of spring groupscould be arranged if desirable.

FIG. 28 shows a practical arrangement of the adjustment of anglediscussed with reference to FIG. 6. In this embodiment, which is awishbone type suitable for a vehicle suspension, the chassis member 130carries bosses 131 which each rotatably support a shaft 132 having ayoke 133 at one end and a lever arm 134 at the other. The yoke 133defines the first journal element and an open rectangular bracket 140,runnioned in the yoke 133, defines the second journal element. A boss135 welded on to the inboard end of each spring blade 136 constitutesthe third journal element and is secured in the bracket 140 by a pin137. The apex ends of the resilient members 136 are fixed in a piercedend fitting 138 capable of taking load. The lever arms 134 are bothconnected by a Y link 139 to a hydraulic ram which is remotely operated.

Operation of the ram 140 causes rotation of levers 134, shafts 132 andyoke 133 to change the angle 6. This means that a driver of a truckcould adjust the ridge height to a required level as the truck is loadedand also be given an indication, by reading the oil pressure required toachieve ride height, of the load carried.

The resilient members used in the FIG. 28 embodiment could be of thetype shown in FIGS. 29, 30, 31 which are a side elevation, plan and endelevation, re-

spectively. The resilient member is a thin walled tube tapering in sideelevation and in plan and changing in section from an elipse at thepivot pin end to a circle at the apex end. This enables greaterresistance to bending while permitting a fairly uniform torsional stresslevel to be maintained along the length of the tube.

When the spring unit is in the form of a Vee it will be appreciated thatthe torque about the longitudinal axis of one arm of the Vee is not inthe same plane as the torque in the other arm. Hence a component of thetwo torques will equilibrate each other but the other components will beadditive and will be balanced by part of the applied load. Thus theequation:

sin U cos 0 will not give the true deflection and it will be modified bythe incorporation of a further term which is a function of B which isthe half angle of the Vee. Moreover, the pattern of energy storagein thestorage cycle will differ from the pattern of energy release during therelease cycle though the total energy stored and given up will be thesame.

It should be understood that the primary and secondary axes can bedefined by rubber bushes in torsion or like devices wherein sliding ofsurfaces over one anothermay not take place. v

The main advantages of the present invention are that it affords springmeans which can be constructed inexpensively from inexpensive materialsand with good scope for unconstrained design.

I claim:

1. A spring assembly consisting of an elongated res'ilient member, firstand second load attachments positioned on the member at spacedlocations, the line extending between them defining a longitudinal axis,said first load attachment being adapted to apply a torque load to saidresilient membensaid second load attachment comprising first, second andthird journal elements wherein said first journal element and saidsecond journal element are connected by primary pivot means for pivotalmovement relative to each other about a primary axis that is inclined tosaid longitudinal axis and the second and third journal elements areconnected by secondary pivot means forv pivotal movement relative toeach other about a secondary axis said third journal element beingintegral with said resilient memher.

2. A spring assembly according to claim 1 wherein said secondary axis isarranged perpendicular to said primary axis.

3. A spring assembly according to claim 2 wherein said secondary axisintersects the primary and longitudinal axes at their junction.

4. A spring assembly according to claim 1 wherein said first loadattachment is adapted to apply linear loads to said resilient member.

5. A spring assembly according to claim 1 wherein said first loadattachment is adapted to apply bending loads to said resilient member.

6. A spring assembly according to claim 1 wherein said first loadattachment is similar to said second load attachment.

7. A spring assembly according to claim 1 having means for varying thespring rate thereof comprising a carrier for said first journal elementmovable to vary the angle between said longitudinal axis and saidprimary axis.

8. An energy absorbing spring assembly according to claim 1 andcomprising two resilient members wherein the first load attachment iscommon to both resilient members and transmits equilibrating torque fromone resilient member to the other and said first journal element iscommon to both assemblies.

9. A spring assembly according to claim 8 wherein said resilient membersare spaced from each other in the direction of the secondary axis andsaid first load attachment is attached to each said resilient membersand transmits equilibrating torque in bending.

10. A spring assembly according to claim 8 having means for varying thespring rate of the unit comprising carrier means for both said firstjournal elements movable to vary the angles between said longitudinalaxes and said primary axes.

11. A spring assembly according to claim 10 wherein said carrier meansis constituted by fourth journal elements which are connected to saidfirst journal elements by tertiary pivot means defining respectivecarrier axes.

12. A spring assembly according to claim 11 wherein said fourth journalelements are movable by remote power means.

13. A spring assembly according to claim 8 having means for holding saidresilient members in a preloaded state.

14. A spring assembly according to claim 13 wherein said preloaded stateis a torsional deflection of the resilient members and said means forholding said resilient members is a stop which prevents their rotation.

15. A spring assembly according to claim 14 wherein said resilientmember is given a pretwist of up to 90 about its longitudinal axis andbetween the secondary axis and the first load attachment.

16. A spring assembly according to claim 14 wherein said first journalelements are mounted in a rotary block capable of rotation in a housingto impart said torsional deflection.

17. A spring assembly according to claim 15 which includes a pluralityof units wherein all of said units have a common first load attachment.

18. A spring assembly according to claim 17 wherein all of said unitshave a common primary axis.

19. A spring assembly according to claim 17 wherein at least two of saidunits have separate primary pivot means defining separate primary axes.

20. A spring assembly incorporating a plurality of units according toclaim 11 wherein each unit is endconnected to another unit.

21. A spring assembly according to claim 20 which includes at least fourunits wherein each unit is connected at one end to another through acommon first load attachment and at the other through a common firstjournal element.

22. A spring assembly according to claim 21 wherein said units all liein a common plane.

23. A spring assembly according to claim 21 wherein at least six unitsare arranged in three dimensional form.

24. A spring assembly according to claim 20 which includes at least fourunits wherein each unit is connected at each of its ends to one otherthrough a load attachment constituted by first, second and third journalelements.

25. A spring assembly according to claim 24 wherein at least four unitsare arranged to lie substantially in a plane.

26. A spring assembly according to claim 24 wherein at least six unitsare arranged in three dimensional form.

27. A spring assembly incorporating a unit according to claim 11 whereinthe angular displacement of the spring through causes an energy inputand a further deflection through 90 causes a release of energy.

28. A spring assembly according to claim 27 wherein a preload equivalentto a predetermined angular displacement of the spring is imposed therebeing pro-, vided a limit stop permitting deflection just in excess of90 to permit the spring to deflect to this limit and stay against it.

29. A spring assembly incorporating a unit according to claim 8 whereinthe resilient member is pretwisted on assembly so that the first ofdeflection causes an energy input and a further deflection through 180causes a release of energy.

1. A spring assembly consisting of an elongated resilient member, firstand second load attachments positioned on the member at spacedlocations, the line extending between them defining a longitudinal axis,said first load attachment being adapted to apply a torque load to saidresilient member, said second load attachment comprising first, secondand third journal elements wherein said first journal element and saidsecond journal element are connected by primary pivot means for pivotalmovement relative to each other about a primary axis that is inclined tosaid longitudinal axis and the second and third journal elements areconnected by secondary pivot means for pivotal movement relative to eachother about a secondary axis said third journal element being integralwith said resilient member.
 2. A spring assembly according to claim 1wherein said secondary axis is arranged perpendicular to said primaryaxis.
 3. A spring assembly according to claim 2 wherein said secondaryaxis intersects the primary and longitudinal axes at their junction. 4.A spring assembLy according to claim 1 wherein said first loadattachment is adapted to apply linear loads to said resilient member. 5.A spring assembly according to claim 1 wherein said first loadattachment is adapted to apply bending loads to said resilient member.6. A spring assembly according to claim 1 wherein said first loadattachment is similar to said second load attachment.
 7. A springassembly according to claim 1 having means for varying the spring ratethereof comprising a carrier for said first journal element movable tovary the angle between said longitudinal axis and said primary axis. 8.An energy absorbing spring assembly according to claim 1 and comprisingtwo resilient members wherein the first load attachment is common toboth resilient members and transmits equilibrating torque from oneresilient member to the other and said first journal element is commonto both assemblies.
 9. A spring assembly according to claim 8 whereinsaid resilient members are spaced from each other in the direction ofthe secondary axis and said first load attachment is attached to eachsaid resilient members and transmits equilibrating torque in bending.10. A spring assembly according to claim 8 having means for varying thespring rate of the unit comprising carrier means for both said firstjournal elements movable to vary the angles between said longitudinalaxes and said primary axes.
 11. A spring assembly according to claim 10wherein said carrier means is constituted by fourth journal elementswhich are connected to said first journal elements by tertiary pivotmeans defining respective carrier axes.
 12. A spring assembly accordingto claim 11 wherein said fourth journal elements are movable by remotepower means.
 13. A spring assembly according to claim 8 having means forholding said resilient members in a preloaded state.
 14. A springassembly according to claim 13 wherein said preloaded state is atorsional deflection of the resilient members and said means for holdingsaid resilient members is a stop which prevents their rotation.
 15. Aspring assembly according to claim 14 wherein said resilient member isgiven a pretwist of up to 90* about its longitudinal axis and betweenthe secondary axis and the first load attachment.
 16. A spring assemblyaccording to claim 14 wherein said first journal elements are mounted ina rotary block capable of rotation in a housing to impart said torsionaldeflection.
 17. A spring assembly according to claim 15 which includes aplurality of units wherein all of said units have a common first loadattachment.
 18. A spring assembly according to claim 17 wherein all ofsaid units have a common primary axis.
 19. A spring assembly accordingto claim 17 wherein at least two of said units have separate primarypivot means defining separate primary axes.
 20. A spring assemblyincorporating a plurality of units according to claim 11 wherein eachunit is end-connected to another unit.
 21. A spring assembly accordingto claim 20 which includes at least four units wherein each unit isconnected at one end to another through a common first load attachmentand at the other through a common first journal element.
 22. A springassembly according to claim 21 wherein said units all lie in a commonplane.
 23. A spring assembly according to claim 21 wherein at least sixunits are arranged in three dimensional form.
 24. A spring assemblyaccording to claim 20 which includes at least four units wherein eachunit is connected at each of its ends to one other through a loadattachment constituted by first, second and third journal elements. 25.A spring assembly according to claim 24 wherein at least four units arearranged to lie substantially in a plane.
 26. A spring assemblyaccording to claim 24 wherein at least six units are arranged in threedimensional form.
 27. A spring assembly incorporating a unit accordingto claim 11 wherein the angular displacement of the spring through 90*causes an energy input and a further deflection through 90* causes arelease of energy.
 28. A spring assembly according to claim 27 wherein apreload equivalent to a predetermined angular displacement of the springis imposed there being provided a limit stop permitting deflection justin excess of 90* to permit the spring to deflect to this limit and stayagainst it.
 29. A spring assembly incorporating a unit according toclaim 8 wherein the resilient member is pretwisted on assembly so thatthe first 180* of deflection causes an energy input and a furtherdeflection through 180* causes a release of energy.